I. Field of the Invention
The present invention relates generally to tool holders and, more particularly, to a combination extension and compression tool holder.
II. Description of the Prior Art
Compression tool holders, such as that disclosed in U.S. Pat. No. 3,658,435 issued on Apr. 25, 1972, are well known and have enjoyed great commercial success in the trade. Such compression tool holders permit the tool, typically a deburring tool, to be retracted relative to the tool holder. Compression tool holders have been found to be particularly useful when used in conjunction with deburring tools. Thus, when the tool holder with a deburring tool is advanced towards an improperly formed workpiece aperture, the deburring tool will retract into the tool holder, thus preventing the deburring tool from being forced into an unfinished hole and thereby broken. Compression tool holders are also particularly useful with deburring tools in that the deburring tool will retract slightly into the tool holder, thereby permitting the deburring tool to dwell at the edge of the workpiece hole to adequately debur the workpiece.
Extension tool holders, such as that described in U.S. Pat. No. 3,761,104 issued on Sept. 25, 1973, have also enjoyed wide acceptance and great commercial success in the trade. Such extension tool holders have also proven to be particularly useful for use in conjunction with deburring tools. During the backstroke of the machine chuck in the deburring of holes, the extension spring compresses due to the engagement of the cutting edge of the deburring tool and the edge of the hole being deburred, allowing the deburring tool to dwell at the back edge of the hole to adequately debur the workpiece.
Although both the previously known compression tool holders and the previously known extension tool holders achieve highly advantageous characteristics, no previously known tool holder has provided for a combination compression and extension tool holder. Therefore, it is the primary object of the present invention to provide a combination compression and extension tool holder.